Previously, Toyota had said that it would begin sales of the plug-in version in Japan in autumn, and that the model would become available in North America and Europe around late autumn.

Sales of the standard version of the fourth-generation Prius, the forefather of the "eco car", have been sluggish in the United States since it went on sale around February, as low gasoline prices have ramped up demand for gas-guzzling SUVs and pick-up trucks.